Method and apparatus for forming transverse welded seams between vertically oriented workpieces

ABSTRACT

The welded seams are formed between facing edges of vertically oriented plate sections by submerged arc welding. The bottom edge of an upper section is formed with intersecting bevelled faces defining a V-shape nose in cross-section, and the upper edge of a lower thick plate section is formed with intersecting sloping faces defining a V-shape upwardly opening notch in cross-section. The sections are placed with the apices of the V-shaped crosssections in substantial alignment vertically to define opposite facing welding grooves having a common welding groove root. The faces defining the welding grooves are arranged at angles such that the welding groove sides diverge outwardly and upwardly from the root. Molten weld metal is progressively deposited along the welding grooves by submerged arc welding while the welding powder is supplied to the grooves both before and behind the pool of molten weld metal. The apparatus includes a welding wire feed guide, contact jaws for conducting current to the welding wire, a conductor for connecting the contact jaws to a source of welding current, and a powder feed pipe in the form of an inverted Y which is fixedly connected with the welding wire feed device. The outlet openings of the powder feed pipe are arranged, respectively, before and behind the contact jaws in the direction of weld formation. A pressure gas may be supplied to the powder feed pipe in advance of the Y junction.

United States Patent [1 1 Fischer et al.

[ METHOD AND APPARATUS FOR FORMING TRANSVERSE WELDED SEAMS BETWEENVERTICALLY ORIENTED WORKPIECES [75] Inventors: Hans Fischer, Nurnberg;Herbert Hellendrung, Oberhausen, both of Germany [73] Assignee:Gutehoffnungshutte Sterkrade Akt.,

Germany [22] Filed: July 2, 1973 21 Appl. No.: 375,868

Related U.S. Application Data [62] Division of Ser. No. 2673146. June28. 1972, Pat. No.

[30] Foreign Application Priority Data June 29. 1971 Germany 2132143[52] U.S. Cl 219/73; 219/126 [51] Int. Cl B23k 9/18 [58] Field of Search219/73, 126, 76, 130, 137,

{56] References Cited UNITED STATES PATENTS 2,277,654 3/1942Merlub-Sobel et al. 219/76 X 2.434.481 1/1948 Anderson 219/136 2.6789875/1954 Talley 219/126 2,810,063 10/1957 Brashear,.1r.... 219/1303,071,678 1/1963 Neely et al 219/76 3,415,975 12/1968 Johnson 219/73 X3.493.713 2/1970 Johnson 219/73 X 1 May 13, 1975 Primary Examiner-.1. V.Truhe Assistant Examiner-Clifford C. Shaw Attorney, Agent, or FirmMcGlewand Tuttle [57] ABSTRACT The welded seams are formed between facingedges of vertically oriented plate sections by submerged arc welding.The bottom edge of an upper section is formed with intersecting bevelledfaces defining a V- shape nose in cross-section. and the upper edge of alower thick plate section is formed with intersecting sloping facesdefining a V-shape upwardly opening notch in cross-section. The sectionsare placed with the apices of the V-shaped cross-sections in substantialalignment vertically to define opposite facing welding grooves having acommon welding groove root. The faces defining the welding grooves arearranged at angles such that the welding groove sides diverge outwardlyand upwardly from the root. Molten weld metal is progressively depositedalong the welding grooves by submerged arc welding while the weldingpowder is supplied to the grooves both before and behind the pool ofmolten weld metal. The apparatus includes a welding wire feed guide,contact jaws for conducting current to the welding wire. a conductor forconnecting the contact jaws to a source of welding current, and a powderfeed pipe in the form of an inverted Y which is fixedly connected withthe welding wire feed device. The outlet openings of the powder feedpipe are arranged, respectively, before and behind the contact jaws inthe direction of weld formation. A pressure gas may be supplied to thepowder feed pipe in advance of the Y junction.

2 Claims, 2 Drawing Figures TATENTEDHAYWSFE 3.883.711

SHEET 10F 2 FIGJ METHOD AND APPARATUS FOR FORMING TRANSVERSE WELDEDSEAMS BETWEEN VERTICALLY ORIENTED WORKPIECES This is a division ofapplication Ser. No. 267,046. filed June 28, 1972, now U.S. Pat. No.3,777,105.

FIELD AND BACKGROUND OF THE INVENTION This invention relates toapparatus for the formation of welded seams extending in a transversedirection. between thick plate cross-sections. particularly when joiningmetal tank sections and forged rings utilizing the submerged arc weldingprocedure.

Heavy apparatus and pressure tanks, for example, re actor vessels,frequently are of such size that they must be initially formed ofseveral components which must be transported. as single parts, to theconstruction site, because of their great weight and large dimensions.When the individual sections are assembled and welded to form tanks, itis frequently necessary, on the con struction site because of lack ofspace, to effect submerged arc welding operations in the transverseposition.

Heretofore, such welding operations have been carried out using onlymanual electrodes, particularly on thick alloyed plates such as tanksections and forged rings. However, this is uneconomical in view ofmodern welding methods, such as submerged arc welding or shielded arcwelding.

The disadvantages of the present manual welding are substantially lowoutput and poor quality of the welded material. for example, slaginclusions, pore formation, and crater cracks, and bonding defects atthe flanks of the seams.

SUMMARY OF THE INVENTION The objective of the present invention is toprovide a welding apparatus permitting welding utilizing the submergedwelding procedure for the formation of transversely extending weldedseams. that is seams which extend in a direction which is perpendicularto the axis of a tank, of tank sections, or of forged rings, even in thecase of thick alloyed plates, and which avoid the above-mentioneddisadvantages.

In accordance with the invention, this problem is solved by producing awelding groove form at the facing plate edges, with the lower surfacesof the welding groove form sloping inwardly and downwardly toward eachother to define a V-shape notch in cross-section. The welding powder issupplied or deposited both before and behind the welding pool, ifnecessary by using a gas under pressure. Advantageously, the angles ofthe sloping edge portions defining the welding groove have a value ofl230.

In accordance with the invention, the apparatus for performing theinvention includes a powder feed pipe in the form of a Y-pipe, withdiverging outlet ends, supported on the guide for the welding wire, theoutlets of the powder feed pipe being arranged before and behind thelower end of the welding wire guide. A special advantage of theinvention is the provision of a pressure gas supply connected to thepowder feed pipe at a point before the outlet ends of the pipe divergefrom each other.

Another object of the invention is to provide an improved apparatus forperforming the method.

A further object of the invention is to provide such an method andapparatus utilizing the submerged arc welding procedure.

For an understanding of the principles of the invention, reference ismade to the following description of a typical embodiment thereof asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. I is a cross-sectional view of the seam form in accordance with theinvention; and

FIG. 2 is a perspective view of the apparatus em bod ying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, which showsthe seam form in accordance with the invention and which permits welduniting plates with a thickness of 200mm and more, as well as forgedrings with a thickness of 300mm and more, by the submerged arc weldingwith transversely extending seams, it will be noted that, in order toobtain a good accessibility for the welding apparatus and for thewelding wire, as well as for the powder feed, the upper edge I of theseam has an aperture angle 0: of 45. The root width at on the side ofthe larger groove portion is about 20mm. It will be noted that the loweredge I of the upper workpiece is formed with intersecting bevelled facesdefining a V-shape, downwardly facing nose in cross-section.

The upper edge 2 of the lower workpiece is formed with intersectingsloping faces defining a V-shape upwardly opening notch incross-section, these faces extending at angles between 25 and 12 to thehorizontal, so that the pouring and holding of the welding powder isfacilitated. The magnitude of the aperture angle a, the magnitude of theroof width a, and the angle [3 of the faces of the upper edge of thelower workpiece provide a very favorable ratio between a very smallwelding volume and a minimum cutting volume. This is of paramountimportance for the economy of the welding, particularly when weldingtransverse seams.

The root width a of the deeper welding groove, to the right in FIG. 1,corresponds to the root width b of the shallower welding groove, to theleft in FIG. I. In contrast to the root width a, the magnitude of theroot width b has been selected to be 10mm higher in order to obtain,after filling the deeper weld groove, to the right in FIG. I, withdeposited weld metal, a better accessibility to remove, for example, theunwelded seam root 6 by planing or grinding. It will be noted that, ineffect, the apieces of the two V-shape sections, namely the nose and thenotch, are substantially aligned vertically, although possibly offset alittle bit relative to each other.

The apparatus of the invention is shown in FIG, 2. The welding powderfeed pipe 4 having downwardly diverging legs 7 and 7a communicatingtherewith, is connected rigidly with the wire feed guide 3, and is soarranged that the welding powder is supplied in sufficient quantitiesboth before and behind the welding pool or welding point, even withnormal weights of the powder charge. This is particularly true forwelding on the upper welding groove edge, where the welding powder,pushed away by the current contact jaws or nozzle 5, which is missing inthe supply range. is supplemented through the second outlet opening 6aof the Y- pipe 7. The Y-shaped powder supply pipe 4 is eliptic in therange of the outlet openings 6, 6a, with the longer diameters oftheellipses extending in the welding direction and with the smallerdiameters of the ellipses corresponding to the diameter of the currentnozzle or jaws 5. By virtue of this, a reduction of the radius of actionin the seam joint can be avoided, and an optimal height of the powdercharge can be maintained, which is absolutely necessary for a pour-freeand slag-free welded joint.

In order to ensure a uniform powder covering, even at shallower pouringangles in the upper and deeper seam regions, the powder feed is effectedwith carbon dioxide gas under pressure. The gas supply pipe is indicatedat 8, and communicates with the powder feed pipe 4 above the point ofdiverging of the discharge legs of the latter,

All metallic components of the powder feeding means are formed ofnon-magnetic material, so that the magnetic field, existing duringwelding in deep seam joints, cannot have any adverse effect on thepouring behavior of the welding powder. Powder feed pipe 4 isdisplaceably mounted, by means of a holder 9, on the insulated ordielectric welding wire feed guide 3. The contact jaws or current nozzle5 are arranged in the same plane as the outlet openings 6 and 6a of pipe4, and between these outlet openings. The welding current supply linefor the entire apparatus is indicated at 10.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. Apparatus for forming transversely extending welded seams betweenfacing edges of vertically oriented thick plate sections, by submergedarc welding, in which the upper edge of a lower plate section is formedwith a longitudinally extending V-groove and the facing lower edge of anupper plate section is formed with intersecting bevelled faces extendinglongitudinally thereof defining a V shape nose with the apex angle ofthe nose being substantially smaller than the apex angle of the facinggroove to provide oppositely facing elongated welding grooves havingupper and lower faces sloping upwardly and diverging outwardly of theplate sections, said apparatus comprising, in combination, welding wirefeed means operable to guide a welding wire downwardly and laterallyinwardly into the welding groove, and including a wire feed nozzleprojectable into the groove; means engaging the welding wire fed by thewire feed means to supply welding current thereto; a welding powder feedpipe fixedly connected to said welding wire feed means; said weldingpowder feed pipe being in the form of a Y-pipe including a downwardlyand laterally inwardly extending stern and downwardly diverging leadingand trailing legs communicating with said steam and dimensioned toproject into the welding groove, and each having a powder dischargeopening at its lower end; said powder discharge openings being arrangedbefore and behind said wire feed nozzle in the direction of movement ofsaid welding apparatus along the welding groove and substantially inalignment with said wire feed nozzle; clamp means secured to saidwelding powder feed pipe and embracing said welding wire feed means foradjustment of said welding powder feed pipe longitudinally of saidwelding wire feed means; and means communicating with the stem of saidpowder feed pipe upstream of the diverging legs thereof and operable tosupply a gas under pressure to the welding powder in said pipe; saidpowder discharge openings being elliptical with the major axes of theellipses extending in the welding direction and their minor axes beingequal to the diameter of the wire feed nozzle; said powder feed pipebeing formed of a non-magnetizable metal; said leading leg supplyingwelding powder into the welding groove in advance of said wire feednozzle, and said trailing leg supplying welding powder into the groovebehind said wire feed nozzle to replenish the welding powder removed bysaid wire feed nozzle.

2. Apparatus for forming transversely extending welded seams, as claimedin claim 1, in which said non-magnetizable metal is a non-magnetizablenickel alloy.

1. Apparatus for forming transversely extending welded seams betweenfacing edges of vertically oriented thick plate sections, by submergedarc welding, in which the upper edge of a lower plate section is formedwith a longitudinally extending V-groove and the facing lower edge of anupper plate section is formed with intersecting bevelled faces extendinglongitudinally thereof defining a V shape nose with the apex angle ofthe nose being substantially smaller than the apex angle of the facinggroove to provide oppositely facing elongated welding grooves havingupper and lower faces sloping upwardly and diverging outwardly of theplate sections, said apparatus comprising, in combination, welding wirefeed means operable to guide a welding wire downwardly and laterallyinwardly into the welding groove, and including a wire feed nozzleprojectable into the groove; means engaging the welding wire fed by thewire feed means to supply welding current thereto; a welding powder feedpipe fixedly connected to said welding wire feed means; said weldingpowder feed pipe being in the form of a Y-pipe including a downwardlyand laterally inwardly extending stem and downwardly diverging leadingand trailing legs communicating with said steam and dimensioned toproject into the welding groove, and each having a powder dischargeopening at its lower end; said powder discharge openings being arrangedbefore and behind said wire feed nozzle in the direction of movement ofsaid welding apparatus along the welding groove and substantially inalignment with said wire feed nozzle; clamp means secured to saidwelding powder feed pipe and embracing said welding wire feed means foradjustment of said welding powder feed pipe longitudinally of saidwelding wire feed means; and means communicating with the stem of saidpowder feed pipe upstream of the diverging legs thereof and operable tosupply a gas under pressure to the welding powder in said pipe; saidpowder discharge openings being elliptical with the major axes of theellipses extending in the welding direction and their minor axes beingequal to the diameter of the wire feed nozzle; said powder feed pipebeing formed of a non-magnetizable metal; said leading leg supplyingwelding powder into the welding groove in advance of said wire feednozzle, and said trailing leg supplying welding powder into the groovebehind said wire feed nozzle to replenish the welding powder removed bysaid wire feed nozzle.
 2. Apparatus for forming transversely extendingwelded seams, as claimed in claim 1, in which said non-magnetizablemetal is a non-magnetizable nickel alloy.